Rider-Built. Track-Proven.
Race-Ready Power. Built by Riders.
603Mods is a hands-on race shop in Rochester, New Hampshire, serving the Seacoast, Lakes Region, and Southern Maine.
We specialize in two-stroke motor builds, race prep, and track-tested support for motocross riders who want more than just a bolt-on upgrade.
Family-Built. Race-Tested. Rider-Trusted.
603mods is a family-run, rider-built race shop based in Rochester, New Hampshire — serving the Seacoast, Lakes Region, and Southern Maine with hands-on service for motocross and two-stroke riders.
We build, prep, and maintain bikes that don’t just look good — they show up when the gate drops. Whether it’s a full race motor, carb rebuild, suspension setup, or mid-week maintenance like chains, sprockets, linkage, and wheel bearings, we keep bikes dialed so racers and parents can stay focused on the weekend.
From the shop to the track, we’re in it with you. If you’ve seen us on race day, you already know — we’re often in the pits helping riders sort issues, fine-tune suspension, or keep things rolling between motos. This isn’t just a service list — it’s what we do, and our chosen lifestyle.
Our Specialized Services
Vapor Honing & Wet Blasting
Cerakote Finishes
Two-Stroke Motor Building
Motocross Race Prep & Bike Setup
Wheel Building
Carburetor Rebuilds & Restoration
Our Work in Action
Explore Our Image Gallery
Rethink Your Race Program
At 603mods, we don’t just build bikes—we build confidence. Whether you’re dialing in suspension, rebuilding a motor, or just need setup advice mid-race day, we’re in your corner. Our race prep isn’t guesswork—it’s decades of real-world experience on the line.
Working with us means joining a tight-knit crew that lives and breathes this sport. We know what works. We know what breaks. And we know how to get you back on the gate.
🧢 Gear Up with 603Mods Merch
Rep the shop. Support the grind. Fuel the team.